Electric switch



T. L, PARKER ELECTRc SWITCH Filed June 1'7, 1955 met. 3, 1935.

T/zomczl. Paf/ier Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE2,023,146 ELECTRIC SWITCH Application June 17, 1933, Serial No. 676,296

4 Claims.

This invention relates to switches, and particularly to a switch wherebya plurality of circuit connections may be established for controllingthe operation `of a heating element, such, for example, as an electricheating pad, or the like.

One object of the present invention is to provide a switch which isconvenient to operate, and which is constructed to insure properpositioning of the various elements embodied in the construction.

Another object of the invention is to provide novel and eliicient meansfor yieldingly securing the relatively movable contacts againstaccidental displacement with respect to the stationary contacts.

A further object of the invention is to provide a structure wherein themovable contacts are combined in an integral unitary structure to insuremaintaining their proper eiiicient relationship at all times.

A still further object of the invention is to improve devices of thecharacter described in sundry details hereinafter referred to andparticularly pointed out in the appended claims.

One embodiment of the present invention is shown for illustrativepurposes in the accompanying drawing, in which Fig. 1 is a face view ofa switch housing embodying features of the present invention and takenfrom the operating side thereof;

Fig. 2 is a plan section taken substantially as indicated by the line 22 of Fig. 3;

Fig. 3 is a transverse sectional elevation taken substantially asindicated by the line 3 3 of Figs. 1 and 2;

Fig. 4 is a detailed elevational view of a through connection employedin the illustrative embodiment of the present invention; and

Fig. 5 is a perspective view of a movable contact element employed inthe present structure.

As shown in the drawing, the housingvof the present invention, indicatedas a whole by the numeral 5, comprises bottom and top members orportions 6 and 1, respectively, adapted to be secured together by meansof screws 8 and 9, or other suitable means, and rigidly mounted in thebottom member 6 is a stationary contact I I and a through connection I2of current conducting material having bindingposts I3 and I4,respectively, by Which the contact I I and through connection I2 may beconnected to a suitable source of current supply through line conductorsI5 and I6, respectively.

Mounted also in the bottom member 6 are a pair of stationary contacts I1and I 8 annullati;r

(Cl. 20o- 11) spaced with reference to each other and to the contact II,the contacts I1 and I8 and the opposite end of the through connection I2being provided with binding screws I9, ZI and 22, respectively, by whichconnection may be made with 5 wires 23, 24 and 25, respectively, of aheating unit such as an electric pad, or the like. The adjacent innerends of the stationary contacts I I, I1 and I8 are shown in the presentinstance as imbedded in the material of the bottom mem- 10 ber 6 andadapted to be engaged by a plurality of movable contacts 26, 21 and 28formed on a movable contact element indicated as a whole by the numeral29 for establishing a plurality of circuit connections within thehousing 5 to ob- 15 tain various degrees of heat in a heating elementcontrolled by the switch.

For supporting the movable contact element 29 .and controlling theposition of the movable contacts 26, 21 and 28, a movable contact car-20 rier, indicated as a whole by the numeral 3I, is rotatably mounted inan aperture 32 formed in the top member 1, and is provided with acentrally disposed axial recess 33 forming a downwardly extendingannular ange 34 having 25 annularly spaced notches 35 formed thereinadapted to. receive the contacts 26, 21 and 28 respectively, with thecentral or body portion of the movable contact element 29 positioned inthe recess 33, the movable contacts 26, 21 and 30 28 overlying thestationary contacts II, I1 and I8, and adapted to be brought intoengagement therewithwhen the carrier 3I is rotated. For manuallyrotating the carrier 3|, an actuating member, indicated as a Whole bythe numeral 35 38, is positioned outside the housing on the upper sidethereof and provided with an elongated projection 31 adapted to engagean elongated recess 38 formed in the upper end of the carrier 3I in amanner to secure the carrier 3I and actuat- 40 ing member 36 againstrelative angular movement, the carrier and actuating member beingsecured against axial movement with respect to each other by means of abolt 39 passing through apertures 4I and 42 formed in the movable cone5tact element; 29 and the carrier 3|, respectively, and being screwthreaded into the actuating member 36, the carrier 3I and actuatingmember 36 being free to rotate together in the .aperture 32 and securedagainst axial movement with re- 50 spect to the housing by shoulders 43and 44 formed on the top housing member 1.

Positioned in the recess 33 and surrounding the bolt 39 between themovable contact element 29 and carrier 3I is a spring 45 adapted toyield- 55 2 ingly urge the movable contacts 26, 21 and 28 mounted in thecarrier 3l into engagement with the stationary contacts II, I1 and I8mounted in the bottom member 6 of the housing.

For conveniently rotating the .actuating member 36, a plurality ofradially extending ribs 46 are formed on the outer or top surface of theactuating member, one of the ribs 46 being provided with an indicator 41adapted to be brought into registry with the indicia Oif, High, Med andLow to indicate the proper connections between the movable contacts26,121 and 28 with the stationary contacts II, I1 and I8 for obtainingthe degree of heat desired in the heating element such as an electricpad, or the like.

For yieldinglysecuring the carrier 3I against accidental rotarymovement, and for maintaining the movable contacts in proper alignmentwith the stationary contacts, yieldable means shown, in the presentinstance, as a resilient flat spring pawl 48 is mounted adjacent one ofits ends in a notch or recess 49 formed in the carrier 3I, and having adetent 5I formed at its opposite or free end adapted to engage annularlyspaced grooves 52 formed in the carrier adjacent the recess 32.

It will be observed that by such an arrangement the carrier 3| andmovable contacts 26, 21 and 28 will be yieldingly secured againstaccidental rotary movement, and that when manual force is exertedagainst the ribs 46 to rotate the carrier, the spring pawl 48 will yieldas the detent 5I is forced out .of one of the grooves 52 and into anannular recess 53 formed in the carrier 3l, and when the carrier hasbeen rotated to establish a new relationship of the movable andstationary contacts, the detent 5I will drop into the next groove 52,thereby yieldingly maintaining the movable and stationary contacts inproper alignment. Y

For insuring proper positioning of the top housing member 1 withrelation to the bottom member 6, the through connection I2 is provided,in the present instance, with a plurality of offset portions 54extending above and beyond the dividingA line between the portions 6 and1 of the housing, and into the top portion thereof, and formed in thetop portion 1 ,are a plurality of inwardly extending ribs 55 positionedtransversely opposite the offset portions 54 of the through connectionI2. Thus, it will be observed that interference between the offsetportions 54 and ribs 55 will be encountered unless the top portion 1 ofthe housing and the bottom portion 6 are assembled in a manner toposition the ribs 55 at the opposite'side of the housing from the offsetportion 54 as illustrated in Fig. 1.

It will be observed from the foregoing description that the presentinvention provides a novel construction and arrangement of movable andstationary contacts by which a plurality of circuit connections may beVestablished within a housing for controlling the degree of heat desiredin a heating pad, or the like, that suitable and eiiicient means areprovided for yieldingly maintaining the contacts in proper alignment,and that suitable means are provided for insuring the proper relativepositioning of the bottom and top portions of the housing and therespective contacts mounted therein.

Obviously, the present invention is not limited to the preciseconstruction and arrangement shown and described as the same may beVariously modied. Moreover, all the features of the invention need notbe used conjointly as the same may be used to advantage in variouslydifferent combinations and sub-combinations.

What I claim as new and desire to cover by Letters Patent is: 5` 1. Inan electric switch, the combination of a split housing comprising bottomand top portions of insulating material, a plurality of annularly spacedrelatively stationary contacts mounted in said bottom portion, a carrierrotatably mounted 10 in said top portion, a plurality of connectedradially extending movable contacts mounted in and bodily movable withrespect to said carrier and engageable with said stationary contacts,means for yieldingly urging said movable contacts to- 15 ward thestationary contacts, an actuating member outside said housing rigidlyconnected to said carrier and rotatable therewith, and yieldable meansmounted on said carrier and engageable 'with said top portion foryieldingly maintaining 20 the carrier in a plurality of relatively fixedpositions with respect to said top portion and maintaining the movablecontacts in alignment with saidV stationary contacts.

2. In an electric switch, the combination of a 25 split housingcomprising connected bottom and top portions of insulating material, aplurality of annularly spaced relatively stationary contacts mounted insaid bottom portion, said top portion having an aperture formed thereinand a plu- 30 rality of annularly spaced grooves adjacent said aperture,a carrier rotatably mounted in said aperture, a downwardly extendingannular flange on said carrier having a Vplurality of annularly spacednotches formed therein, a plurality of con- 35 nected radially extendingcontacts Vmounted in said notches and bodily movable with respect tosaid carrier and engageable with said stationary contacts, resilientmeans mounted in said carrier for urging the movable contacts towardsaid 40 stationary contacts, an actuating member outside said housingrigidly connected to said carrier, and a resilient pawl mounted in saidcarrier and having a free end portion adapted to engage the grooves inthe top member adjacent the aper- 45 ture formed therein for ,yieldablymaintaining the carrier in a plurality of positions with respect to thetop portion, and maintaining the movable contacts in alignment with thestationary contacts for establishing a plurality of circuit con- 50nections within the housing.

3. In an electric switch, the combination of a split housing comprisingbottom and top portions, fastening means operatively related to therespective portions for securing the portions together, 55 a pluralityof annularly spaced relatively station-v ary contacts and a throughconnection having binding screws associa-ted therewith mounted in saidbottom portion, said through connection having an offset portion formedthereon and extend- 60 ing beyond thev dividing line between theportions of the housing and into the top portion thereof, an inwardlyextending rib formed on the top portion on the opposite side of thehousing from` said offset portion of the through connection and 65engageable therewith when said top and bottom portions of the housingare arranged in improper relationship, a carrier rotatably mounted onsaid top portion, a plurality of connected movable contacts mounted insaid carrier and engageable 70 with said stationary contacts, anactuating member outside said housing rigidly connected to said carrierand rotatable therewith, and yieldable means operatively related to saidcarrier and top portion for yieldingly maintaining the carrier in 75positions with respect to said top portion and maintaining the movablecontacts in alignment with the respective stationary contacts forestablishing a plurality of circuit connections within the housing.

4. In an electric switch, the combination of a split housing comprisingbottom and top portions, fastening means operatively related to therespective portions for securing the portions together, a plurality ofannularly spaced relatively stationary contacts and a through connectionhaving binding screws associated therewith mounted in said bottomportion, said through connection having a plurality of offset portionsformed thereon and extending beyond the dividing line between theportions of the housing and into the top portion thereof, a plurality ofinwardly extending ribs formed on the top portion transversely oppositethe oifset portions of the through connection and engageable therewithwhen said top and bottom portions o'f the housing are arranged inimproper relationship, a carrier having an elongated depression formedtherein rotatably mounted in said top portion, a plurality of connectedradiallyl extending movable contacts mounted in and rotatable with saidcarrier and engageable with said stationary contacts, an actuatingmember outside said housing having an elongated projection positioned insaid depression, means for rigidly connecting said carrier and actuatingmember together, and yieldable means mounted on said carrier andengageable with said top portion for yieldingly maintaining the carrierin a plurality of positions with respect Vto the top portion andmaintaining the movable contacts in alignment 15 with the respectivestationary contacts for establishing a plurality of circuit connectionsWithin the housing.

THOMAS L. PARKER.

